The very best SIM only deals and plans for May 2018

We pick the best SIM only deals so you don't have to. Use the T3 comparison chart to tailor your perfect tariff.

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If you want a great contract-free deal, you've come to the right place. SIM only deals are great because they enable you to use the phone you want with the network you want. 

What's more, they often enable you to save on your data, calls and texts with a tariff that best suits you. And they're available from all networks - Vodafone, O2, Three, EE, Virgin, Giffgaff, iD, Tesco and BT. 

Some providers refer to SIM only deals as 'Pay Monthly'. In reality, it's not just Pay Monthly deals that are available - there's some with 12 month rolling contracts as well as others that are PAYG (Pay As You Go).

Usually for SIM only deals you can get SIM cards in all sizes, but many networks are increasingly moving over to nano SIMs as these become ever more popular among handset manufacturers. Anyway, enough from us - check out the best SIM only deal for you!

Tailor your perfect SIM only deal:

 What is SIM only? 

The most important bit of your phone is a little chip that you stick inside it: the SIM card. SIM is short for Subscriber Identity/Identification Module, and it’s the key to getting your phone to do anything. Without a SIM you can’t connect to a mobile phone network to make calls or use your favourite apps.

When you buy a phone on contract you’ll be given the appropriate SIM by your network provider, but if you buy your phone SIM-free or want to change providers once a contract is over then you should look for a SIM only deal. That’s when you already have the phone and just need a SIM card to get connected.

The first thing to think about when considering a SIM only deal 

The first thing to consider is the network, especially if your phone originally came on contract: many phones are locked to specific networks, so for example a phone locked to Vodafone won’t accept a SIM from Three. That doesn’t mean it can’t accept the SIM, but you’ll need to get the network lock removed by your friendly neighbourhood phone fixer first. 

You should also pay close attention to the network’s coverage to be sure you can get coverage in the places you’re likely to be. Many smaller operators piggyback on the big-name networks, so for example GiffGaff uses O2’s network and Carphone Warehouse’s ID Mobile uses Three.

What to look for when you’re considering SIM only deals

There are four key things to consider when you’re comparing SIM only deals: price, data, inclusive minutes and contract length.

We’ll start with contract length, because that’s important: some of the cheapest deals depend on you signing a fixed term contract, which may not be ideal if you don’t know what your average monthly usage is going to be. If you can’t predict what you’ll use, an initial one-month SIM only contract makes a lot of sense.

Know what you need

Once you do know your average usage, it’s time to delve into the details. Data is the biggie for us: we regularly use massive amounts of data and leave our mobile phone calling minutes almost entirely untouched. Look at how many minutes you use, how many texts you send and how much data you download and then focus on deals that provide the right amounts of each: exceeding allowances can be an expensive business. Make sure that you know exactly what kind of calling minutes you’re buying too: are your minutes cross-network? Does the text bundle include picture messages, or are they charged at 50p per picture? Always look at the small print to see exactly what you’re paying for and what the penalties are for exceeding any allowances. 

The devil’s in the detail

Price sounds obvious, but keep an eye out for special deals. For example, some low-priced SIM only deals offer fairly generous cashback, and others don’t. Some comparison services list effective prices after the cashback is applied, which can distort listings somewhat. Others bundle paid-for services such as Spotify or Apple Music, which can make the deals much more attractive.

Last but not least, don’t forget about SIM size. Older phones’ SIM card slots are larger than the most recent ones, so you’ll need to know whether you need a standard, micro or nano SIM. Some operators offer clever SIMs that can be popped out to make all three sizes.

 The best handsets for SIM only 

You can get SIM only deals for almost any phone, but you’ll find the biggest savings compared to contract deals when you’re talking high-end handsets such as iPhones, Samsung Galaxy phones, Sony Xperia handsets and so on: by buying your phone and your SIM separately you can save enormous amounts of money, not least because SIM only deals tend to offer more options. For example, contracts with decent data allowances tend to have very high allowances for calls and texts too, but if you don’t need that you can find a SIM only deal with tons of data that doesn’t expect you to pay for the calls and texts you won’t make. It definitely pays to shop around.

1. The absolute cheapest SIM only deal out there

iD Mobile | 1 month contract | 250MB data | 250 minutes | 5000 texts | £4 per month

This is the cheapest SIM only deal currently available in the UK. If you just need to keep a phone up and running for occasional use, this is a good option. Clearly 250MB is not much data at all so you'd be advised to either keep mobile data switched off or else be careful what apps are updating in the background. Between 11th April until 8th May, customers will also be entered into a prize draw for £5k Currys PC World vouchers. BUT WAIT, CHECK OUT THE NEXT DEAL FIRST!

View this deal: at iD Mobile

sim only deals

2: The best 1GB SIM only deal

iD | 1 month contract | 1GB data | 250 minutes | 5000 texts | £5 per month

For just £1 extra a month over the above deal, you can get 1GB of data instead of 250MB, which is much better value if we're honest. This SIM only deal allows for much more freedom to enjoy a bit of data away from Wi-Fi such as checking emails, browsing the net or even a bit of Google Maps when needed. Be careful what apps are updating in the background though (just tell your phone to do this while on Wi-Fi only).

View this deal: at iD/Carphone Warehouse

sim only deals

3: The best 5GB SIM only deal

iD | 1-month contract | 4GB data | 500 minutes | 5000 texts | £10 per month

iD doesn't just do cheap 1GB SIM only deals. You can also get a generous 4GB for just £10 a month. And because it's a one-month SIM only contract, you can cancel at any time.

View this deal: at iD/Carphone Warehouse

sim only deals

4: The best 12GB SIM only deal

Talk Mobile | 12-month contract | 12GB data | 5000 minutes | 5000 texts | £12 per month

If you're happy to sign up for 12 months you can get an excellent deal at just £12 a month for a whopping 12GB of data. That's quite a leap up in data from Talk Mobile's 30-day deal above for 4GB of data at £10 a month. Happy with your phone? This is excellent value for a 12 month deal.

View this deal: at Talk Mobile

5: The best best 25GB SIM only deal

Vodafone | 12-month contract | 20GB data | Unlimited calls and texts | 12 months of Sky Sports mobile, Now TV or Spotify | £20 per month

Vodafone's deals have been a bit pricey of late but we think the extras are well worth a look here. In addition to the massive 20GB of data, you get to choose between Sky Sports mobile, Now TV or Spotify for 12 months of free access. There's 4GB of roaming data too!

View this deal: 20GB Vodafone SIM only deal

6: The best unlimited data SIM only deal

Three | 12 month contract | Unlimited data | Unlimited texts | 200 minutes | £22 per month

Sometimes, you've just gotta have all the data. Netflix marathons, epic Pokemon Go quests, constant Spotify tunes, this all you can eat data bundle is ideal for the serious mobile user who never needs to worry about poxy thing like data allowances or Wi-Fi. Shame about the comparatively low minutes offered, but how often do you use your phone as a phone nowadays? At least there's a £30 cashback incentive to claim.

View this deal at:

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